ML19308C736
| ML19308C736 | |
| Person / Time | |
|---|---|
| Site: | Vogtle, 05000426, 05000427  |
| Issue date: | 12/20/1979 |
| From: | Johnson T Office of Nuclear Reactor Regulation |
| To: | Hulman L Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8002010220 | |
| Download: ML19308C736 (3) | |
Text
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g(f* "%,h, T[fG UNITED STATES NUCLEAR REGULATORY COMMISSION 3
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-l WASHINGTON, D. C. 20555
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2 g ws Docket Nos. 50-424 DEC and 50-427 MEMORANDUM FOR:
L. G. Hulman, Chief Hydrology-Meteorology Branch, DSE THRU:
W. S. Bivins, Leader I[-
Hydrologic Engineering Section, HMB, DSE FROM:
T. L. Johnson, Hydraulic Engineer Hydrologic Engineering Section, HMB, DSE
SUBJECT:
SITE VISIT TO V0GTLE NUCLEAR PLANT On December 4-5, 1979, I visited the Vogtle nuclear plant site. The purpose of the visit was to evaluate the erosion and damage which had occurred to the Category I backfill and slopes within the excavation due to runoff from heavy rainfall.
My presence at the site was requested by I&E, Region II.
On December 4, I met with officials of Georgia Power Company and Bechtel Corp.; an attendance list is attached.
The subjects discussed included sub-surface water conditions, methods of handling subsurface water, surface runoff, evaluations of foundations, settlement monitoring, PSAR reviews, responses to NRC questions, and additional data requirements.
On December 5, we were given a tour of the site. We viewed the erosion damage to the slopes and structures and were escorted to various parts of the site.
It was at this time that I noted the apparent cause of excessive surface runoff into the excavation.
It appeared that two culverts at the northwest corner of the drainage ditch immediately to the west of the excavation had been clogged.
With the culverts clogged, the surface water was found to flow overland and spill down the northwest access ramp.
This excessive water apparently overtaxed the existing diainage capability and overflowed into critical portions of the excavation, in the vicinity of the control building and reactor buildings.
No other si jnificant flow pathway was apparent.
After the site tour, a meeting was held to discuss what had been learned.
I explained to them my opinion as to vhat had caused the excessive foundation damage.
I suggested several methods which could be utilized to prevent water from overflowing the ditch and spillug down the access road. The methods 8002016 M t
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_.7 L. G. Hulman 4 suggested included the construction of a berm or the raising of the road.
I explained that cleaning out the culverts would not completely rectify the problem, because during construction loose materials are lying about every-where and a heavy rainfall would simply bring about a reclogging of the culverts during the storm. Significant credit.should, therefore, not be given to the flow-carrying capability of the culvert.
The need for a design which prevented the entrance of surface water from outside the excavation was agreed to by the applicant.
I further suggested that a design analysis for the type of protection selected should be subalitted for NRC review.
This was also agreed to at the meeting.
f d a x. -
6 T. L. Johnson, Hydraulic Engineer Hydrologic Engineering Section Hydrology-Meteorology Branch, DSE
Attachment:
As Stated cc: w/ attachment D. Vassallo S. Varga C. Stable H. Thornburg R. Shewmaker J. O'Reilly C. Murphy F. Cantrell M. Hunt J. Harris J. Lenahan F. Schroeder J. Knight F. Schauer S. Chan L. Hulman W. Bivins T. Johnson R. Jackson L. Heller L. Reiter
MEETING ATTENDANCE RECORD GEORGIA POWER COMPANY ET. AL AND NRC, DISCUSSION OF EROSION DAMAGE December 4 & 5, 1979 Bechtel Resident Civil Engineer Don Armstrong Bechtel Chief Soils Engineer Walter Ferris Bechtel Civil Engineer Mike Pervoich Bechtel Jim Mah1meister -
Site Resident Engineer Bechtel Assistant Project Engineer Mike Thakar GPC Project General Manager Doug Dutton SCSI Nuc. Safety & Licensing Mgr.
Jim Bailey GPC Harry Gregory Asst. Construction Project Mgr.
GPC Susan Matthews -
Engineering Supervisor Consultant - Fugro Bob Bush Bechtel Soils Engineer Vas Srinviasan GPC Construction Project Manager Kan Gillespie GPC Area Engineer, Civil Roger Duncan GPC Project Section Supervisor, Civil Bennie Harbin Bechtel Geologist Roy Kiser Bechtel Resident Engineer, Civil Jim Lovekamp GPC Ed Groover Q.A. Site Supervisor NRC, Region II: I&E Reactor Const. Inspector Jack Harris NRR - Geosciences Geotechnical Engineer Owen Thompson NRR - HMB, DSE Hydraulic Engineer Ted Johnson i
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JAN I11980
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